AES-256 encrypted transactions and PCI-certified by Stripe

Security at Stripe
Stripe has been audited by a PCI-certified auditor and is certified to PCI Service Provider Level 1. This is the most stringent level of certification available in the payments industry. To accomplish this, we use the best-in-class security tools and practices to maintain a high level of security at Stripe.

HTTPS and HSTS for secure connections
Stripe forces HTTPS for all services using TLS (SSL). We regularly audit the details of our implementation, including the certificates we serve, the certificate authorities we use, and the ciphers we support. We use HSTS to ensure that browsers interact with Stripe only over HTTPS. Stripe is also on the HSTS preloaded lists for both Google Chrome and Mozilla Firefox.

Encryption of sensitive data and communication
All card numbers are encrypted at rest with AES-256. Decryption keys are stored on separate machines. None of Stripe’s internal servers and daemons can obtain plaintext card numbers but can request that cards are sent to a service provider on a static allowlist. Stripe’s infrastructure for storing, decrypting, and transmitting card numbers runs in a separate hosting environment, and doesn’t share any credentials with Stripe’s primary services (API, website, etc.).